Anatomia e histoquímica do caule de espécies conhecidas como quebra-pedra das famílias Euphorbiaceae e Phyllanthaceae

This study aimed to provide structural and histochemical information about the stem of species popularly known as “stone breaker”, found in the municipality of São Mateus (ES). The species analyzed were Euphorbia prostrata Aiton., Euphorbia hyssopifolia L., Phyllanthus amarus Schumach. & Thonn and Phyllanthus tenellus Roxb. Vouchers were collected on the Campus of the Federal University of Espirito Santo and in the Sernamby neighborhood. For the analysis, cross sections were performed between the 2nd and 5th nodes, to describe the primary growth, and between the 9th and 10th nodes, for secondary growth. Tests were carried out to detect starch, chemical composition of crystals, total lipids, latex, non-structural phenolic compounds and lignin. As for anatomical analyzes, only E. prostrata presented trichomes, which are of the tector type. Only in the species of Phyllanthus crystals were observed. Euphorbia species are differentiated by the presence of laticiferous channels. Histochemical tests revealed accumulation of starch grains, showing the amyliferous sheath of P. amarus and phenolic compounds only in the epidermis of E. prostrata. Anatomical and histochemical studies are of great relevance for the knowledge and differentiation of the species known as stone breakers, and may assist in the identification of other species with the same popular name.